The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
With the development of electronic technologies, transmission attenuation of a high frequency signal is mainly affected by a medium during transmission of an electrical signal. A fundamental reason thereof is that the high frequency signal is related to a dielectric constant of the medium, and a lower dielectric constant of a medium indicates better high frequency signal transmission. For conventional media, a liquid crystal polymer (LCP), Teflon or a pure adhesive with low relative permittivity are usually used as a substrate layer to wrap a signal line.
However, a dielectric loss of the foregoing materials is still relatively large, resulting in large signal attenuation of a transmission line of a circuit board made of these materials. In addition, Teflon and the LCP are special materials with high material costs. In addition, a conventional signal conductor is provided above or below a dielectric layer, and such arrangement thickens the circuit board and makes flexibility of the circuit board decrease.
Therefore, a heretofore unaddressed need to design a novel circuit board exists in the art to address the aforementioned deficiencies and inadequacies.